A Nashville crayfish, also known as Orconectes shoupi, enjoys the sunshine in Mill Creek in Nolensville. / File / The Tennessean

Written by

Bonnie Burch

The Tennessean

BRENTWOOD — A small lobster-like creature once again is affecting a big development project.

The Nashville crayfish, which was listed as endangered by the U.S. Fish and Wildlife Service in 1986, will force changes to construction schedules for work on two bridges that go over Mill and Owl creeks as part of an effort to widen Concord Road.

Though the widening project won’t be delayed due to the state’s only federally endangered crayfish, construction crews will have to change the order in which they work on some tasks on those bridges to allow the crayfish time to hatch and rear their young as part of their annual reproductive cycle, which lasts from October until the end of May, said Dennis Crumby, a biologist with the Tennessee Department of Transportation, which is widening the road that runs through Brentwood.

“And really, it’s no big deal because this is a two-year job. It hasn’t caused a delay, just a reshuffling in the contractor’s schedule. Instead of working on the culverts, which we typically do in the late summer and fall — the low water season — we’ll just come back to those locations in June,” Crumby said.

Once crews are allowed to get near the water, licensed professionals will collect any Nashville crayfish that they can find in the bridge work area and relocate them upstream before the concrete piers are poured.

The plans to protect the Nashville crayfish — which are differentiated from other crawfish species in the area by their saddle-back markings — were long on the radar for TDOT. Any time a project receives federal dollars, the state road and highway department must coordinate with the Fish and Wildlife Service to make sure that endangered and threatened species are accounted for before anything is approved.

Work underway

The construction project, which has just gotten started with surveying and the removal of several trees near the current roadway, is expected to be completed by early summer 2016, said TDOT spokeswoman Deanna Lambert.

No one knows how many Nashville crayfish live here. But it was listed as endangered mainly because the only place the Orconectes shoupi is known to exist in the world is in the Mill Creek watershed in Davidson and Williamson counties.

“It’s not a rare animal where it lives. It’s actually pretty prominent. But if you had an incident, say a diesel accident, and it got into the Mill Creek system, you could really negatively affect this species. It’s also because it exists in a developing area that this is such a threat,” Crumby said.

The May 2010 flood probably didn’t harm the Nashville crayfishes.

“I don’t think the flood did much to them. They love slab rock, which are these large, flat boulders under water. That’s their primary habitat. But sometimes you’ll find them in the undercut banks among the weeds. They’re pretty territorial and are really good at defending that territory against other crayfish. Once in a while, they’ll come out and wander around a little to look for food,” he said.

Common concern

Concord Road isn’t the first construction project to face realignments or delays due to the potential presence of the endangered crustacean.

In 2007, developers of the Wal-Mart Supercenter on Nolensville Road built six bridges in front of the building to preserve the crayfish.

In Nolensville, projects such as Sunset elementary and middle schools, which opened in 2005, were delayed by crayfish preservation, and the town’s historic district’s plan to bring sewer lines across Mill Creek was held up in 2009 so they wouldn’t interfere with the crayfish reproduction cycle.

In 1998, developers of The Governors Club subdivision were fined $202,500 by the state for allowing excess soil to wash into a stream, damaging crayfish habitat. The crayfish delayed the construction of the gated-subdivision’s Arnold Palmer-designed golf course, and two holes near Crockett Road had to be realigned to avoid an unnamed creek that ran through the property.

“This is not something new. We’ve been doing this process for quite a few years. I remember we did something similar for the bridge over I-40 near Fesslers Lane. We also do this for freshwater mussels and fish that we have to consider,” Crumby said.